Use transient_internet() consistently in test_imaplib

Lib/test/test_imaplib.py

@@ -219,9 +219,11 @@ class RemoteIMAPTest(unittest.TestCase):
 
     def tearDown(self):
         if self.server is not None:
+            with transient_internet(self.host):
                 self.server.logout()
 
     def test_logincapa(self):
+        with transient_internet(self.host):
             for cap in self.server.capabilities:
                 self.assertIsInstance(cap, str)
             self.assertTrue('LOGINDISABLED' in self.server.capabilities)
@@ -230,6 +232,7 @@ class RemoteIMAPTest(unittest.TestCase):
             self.assertEqual(rs[0], 'OK')
 
     def test_logout(self):
+        with transient_internet(self.host):
             rs = self.server.logout()
             self.server = None
             self.assertEqual(rs[0], 'BYE')
@@ -240,6 +243,7 @@ class RemoteIMAP_STARTTLSTest(RemoteIMAPTest):
 
     def setUp(self):
         super().setUp()
+        with transient_internet(self.host):
             rs = self.server.starttls()
             self.assertEqual(rs[0], 'OK')